We plan to continue the study of the relation between syntax and phonetics in human speech processing. Experiments on speech production will be conducted to test how speakers' syntactic representations of an utterance constrain the phonetic representation of two prosodic variables, duration and fundamental frequency, in addition to constraining cross-word rules of phonetic conditioning. In studiesof speech perception, experiments will be aimed at (a) whether listeners utilize syntactically-constrained acoustic information to recover and predict structural relations, and (b) whether listeners normalize for prosodic information over domains that are syntactically defined. Studies of speech production will relay on computer-aided techniques of acoustic analysis. In studies of speech perception, stimulus materials will include natural speech which has undergone electronic editing and/or resynthesis, also accomplished by computer. The research shouldpermit an elaboration of a theory of speech processing which can be applied to certain practical problems, including speech synthesis and the training of deaf children's speech.